Heat exchange system



Feb. 1, 1966 1. F. KoHN 3,232,281

HEAT EXCHANGE SYSTEM Filed Deo. '7, 1964 2 Sheets-Sheet l TO APPROPRIATE HorwAn-:Ron STEAM uT|| |zATloN l ,.36 oEvvcEs 28\ l PUMP 1-1 THERMOSTAT 38 \j l:\\ 1r"" TTT- h1 l C l l: z/2 TRUE i I l 1 *TTI-: w-w: /ll g I3 I l l lw -L l I; Il [(f l `:`32 L Alf- 1 I l il I I I4 f W i 7 43/ Q Q Q f4 ATTORNEYS Feb. 1, 1966 J. F. KOHN 3,232,281

HEAT EXCHANGE SYSTEM Filed Dec. '7, 1964 2 Sheets-Sheet 2 INVENTOR. J O H N F. KO H N ATTORNEYS United States Patent O 3,232,281 HEAT EXCHANGE SYSTEM .lohn Francis Kohn, 147 Williams St., Bedford, Ohio Filed Dec. 7, 1964, Ser. No. 416,576 2 Claims. (Cl. 122-494) This invention relates to heat exchange systems and, more particularly, to a new and novel boiler to be used therewith.

In the usual and customary heating system a boiler which takes on a customary tank design is utilized. The boiler being designed to withstand pressures and to transmit heat developed by combustion of a fuel to heat water or generate steam. In some instances the liquid in the boiler may be something other than water; however, for purposes of this invention we shall limit our attention to water heating or steam generating types of boiler systems. It is, of course, important that the boiler hold its contents safely and deliver the steam or hot water to the desired location for utilization. It is further desirable, from the standpoint of economy, that the water contained in the boiler be heated in a minimum amount of time and that the water remain at the desired heat level with a minimum of fuel expenditure,

The customary type of steam or hot water boiler is an external combustion device, in that the combustion takes place externally from the region of the boiling water. This fact implies the existence of a surface separating the interior of the boiler from the fuel combustion zone. All of the heat which reaches the water must be transferred through this surface. This surface being called for purposes of this description the heating surface. Heat which is generated by combustion may be transferred to the heating surface in two ways. The surfaces which might be said to be in communication with the incandescent region of combustion receive heat at a rapid rate by radiation. Other portions may receive heat by convection from the products of combustion which have been heated in the furnace and act as vehicles for transportation of heat to the boiler surface. The heat is transferred by conduction from the gas side of the heating surface through the metal heating surface to the water contained in the boiler.

In the simple cylindrical shell type of boiler, which is heated with flames supplied through the outer lower surface, many and varied forms and types of boilers have been evolved. However, it has been a characteristic of all of the boilers used that the water contained therein is heated by way of conduction from the burner through the metal plate. The heat gradually rises through the water itself to accomplish a total heating thereof. This has proved to be an unsatisfactory way of heating the water contents of a boiler since, not only is an unduly long time needed to heat the total contents of the tank, but at the same time, a large expenditure of fuel is necessary to maintain the water at the desired temperature once it has been reached. It is a general object of this invention to overcome these and other shortcomings of prior type of boiler systems.

lt is another object of this invention to provide a boiler system which is of unique design and provides substantial heating surfaces at various levels of the boiler to accordingly permit the contents of the boiler to attain the desired temperature in a minimum amount of time.

It is still another object of this invention to provide a boiler system which is of unique design and thus requires a minimum of fuel expenditure to maintain the contents of the boiler at the desired temperature once it has been reached.

Another object of this invention is to provide a boiler system design which is capable of usage with existing heating systems.

ICC

It is still another object of this invention to provide a boiler system which is of simple and economic design and accordingly means for utilization in modern home heating systems.

Other objects and advantages will appear in the course of the specification and with all of the said objects and advantages in view, this invention consists of the several novel features hereinafter fully set forth and more particularly defined in the appended claims.

In accordance with these objects and iirst brieiiy described the invention includes a boiler heating arrangement consisting of a burner, and conventional air intake means therefor. In addition, a pilot light is provided for ignition of the burner. A suitable temperature sensitive control means, which in turn is controlled into its activated state by a thermostat, is connected between the burner fuel supply and the burner. Accordingly, thermostat detection of a difference between the actual temperature and the desired temperature on the control means will be activated to permit supply of fuel to the burner. Ignition of the burner is accomplished by the pilot. In addition, a proper venting means for the burner is provided to assure that the pressures in the burner system, as well as gas accumulations therein, do not approach a dangerous state. There is also provided a proper pressure sensing device to be able to gauge the pressure of the boiler and to take appropriate steps if the system approaches an undesirable high pressure level. Also a suitable pump is provided to permit transfer of the heated water, if a hot water system is desired, to the utilization devices after the proper temperature of the water has been reached inside the boiler. If the system is to be used to provide steam heat to a home, it is, of course, necessary that utilization means be provided at the uppermost part of the boiler, where the steam collects, and also a fresh feed water supply must be introduced to the boiler to take the place of all steam generated and withdrawn from the boiler so that the water level will be maintained at the proper position. In addition, safety devices to protect against low water and high pressure must be provided. in addition to these safety devices, boilers are equipped with other auxiliaries such as drive pipes to filter the entrained droplets of water from the steam and deliver dry steam at the steam nozzle, water level gauge, drain and blow-down connections and steam pressure gauges are also provided. Lastly, the system includes an outer air enclosing chamber which surrounds an inner fluid containing chamber. The inner fluid containing chamber is, of course, leakproof to prevent the escape of the liquid contained therein into the outer chamber which surrounds it. Mounted into the wall of the boiler at differential elevational positions are a plurality of superimposed rows of tubes. Each of the plurality of rows are made up of a number of individual tubes in parallel relationship to each other. The axes of the tubes in immediate adjacent rows are in substantially transverse relationship to each other. The plurality of rows of tubes provide the means by which hot air convection currents are in communication with practically the entire liquid content of the boiler to accomplish substantially concurrent heating thereof.

The invention is clearly illustrated in the drawings accompanying the specification, in which:

FIG. l is an elevational view, with parts broken away, of a heat exchanger embodying my novel boiler structure and clearly showing the same, as well as diagrammatically showing the necessary control system therefor; and

FIG. 2 is a transverse sectional View taken along the section 2-2 of FIG. 1.

Referring now more particularly to the embodiment illustrated in the drawings, the form there shown comprises an outer chamber formed by rectangular body 11. Body 11 is suitably sealed to prevent any heat transfer from occurring therethrough into the atmosphere. The rectangular housing 11, defining by the Wall structure as shown, encloses therewithin the novel and ingenious boiler structure generally shown by the numeral 12, see also FIG. 2 for a better View of the transverse tube relationship. It is, of course, obvious that the outer rectangular housing 11 may be made of any suitable material and sealed in an appropriate manner to prevent heat transfer therethrough. Formed integral with the lower portion of housing 11 is burner chamber 15, with the bottom 16 of boiler 12 defining the heating surface or upper surface of the burner chamber 15. Burner 18 which may be of standard commercial design is positioned in operable fashion in burner chamber such that the flames generated thereby will be in contact with the heating surface 16 of the boiler, and, accordingly, provide heat to the water contained therein by means of conduction from the gas side of the heating surface 16, through the metal 16 to the water. Cutoff valve 23 is provided in the gas supply line, and is operative to control the feeding of gas therethrough. Further control of the valve is by way of control means 24, which is shown diagrammatically to be in circuit with the fuel supply line 25 to burner 18.

To provide the proper amount of air to burner chamber 15 and accordingly permit combustion to occur therein air intake ports 22 are provided for communication with the outer atmosphere. Also in order to prevent the dangerous collection of unburned gases as well as to relieve any pressure developed in the burner chamber a tlue passage 33 is provided to supply communication of the burner chamber with the outer atmosphere and provide the necessary venting of the burner chamber 1S. A drain line 30, controlled by valve 26, is provided at the lower extremity of the boiler housing 12 to permit rapid discharge of the Water contained therein for cleaning purposes or for any other desired end. A chamber 11 pressure indicating gauge and vent 27, permitting continuous indication of the pressure conditions in the chamber, is also provided as shown in FIG. 1.

In addition, if the system is to be used to supply hot water, a suitable water pump 36 is connected in the hot Water supply line to provide a closed system therewith. Additionally, appropriate tap-off devices at the desired hot water discharge points may also be provided, this being generally indicated by numeral 48. It should, of course, be appreciated that a by-pass valve 38 and temperature gauge 37 may be provided in the hot water output lines for continuous monitoring and selective cutoff, should that be desired. In the event that the circuit is to be used as a steam heat supply unit it, of course, is obvious that pump 36 would not be needed, and, in such a case, a suitable uid supply would be necessary to provide selective amounts of makeup liquid to take the place of the steam generated and withdrawn from the boiler.

Also, in a heating system usage of my invention, a heat sensing device such as a thermostat 28 is provided for activation of control means 24. Thermostat 28 works in a conventional manner and is, accordingly, settable to the heat desired by the home occupant. Upon a differential, between the actual heat conditions and the desired heat conditions, existing thermostat 28 is responsive to generate an energization signal to control means 24. Control means 24 being any suitable valve operating device which is normally in an olf state, and is responsive to a signal from thermostat 28 to assume a valve activation state for the duration of the thermostat signal. Activation of control means 24 opens valve 23 and permits fuel to ow to burner 18. Upon the system providing the desired amount of heat thermostat 28 is responsive thereto to deenergize control means 24, and, accordingly, prevent further burner 18 ignition. This operation is in accordance with standard burner systems and, accordingly, further description is not deemed necessary. A further safety control feature includes thermocouple 19 which is mounted proximate to pilot 21, in ame sensing relationship thereto. Thermocouple 19 is the master control of control means 24 and disables operation of means 24, notwithstanding a signal being generated by thermostat 28, if a pilot ligllt failure has occurred. This control is obviously essential since we do not want the feeding of fuel to burner 18 if pilot 21 is out. Turning now to the unique design of the boiler chamber 12, We find that in the preferred embodiment shown in FIGS. 1 and 2 it takes on a rectangular form, however, it should be understood that any suitable form may be utilized, and this form is merely shown as the preferred embodiment but is not intended to limit the scope of my invention.

Furthermore, integrally formed in water tight relationship to the walls are a plurality of rows of tubes 13 and 14. T-ubes 13 extend between walls 41 and 42, and tubes 14 extend between walls 43 and 44, see FIG. 2. FIGS. 1 and 2 clearly indicate that the rows of tubes 13 and 14 are alternately transverse to each other, along the elevational dimension of burner 12, to thus provide maximum heat transfer flow paths for hot air convection currents, while at the same time ensuring substantially boiler rigidity. As an alternative, either set of alternate rows 13 or 14 may be eliminated or all of the rows of tubes may extend parallel relationship to each other instead of alternate parallel relationship as shown.

It the alternative mode of operation is utilized, that is to say the system is used as a hot water supply system and not to heat a home, for example, then of course, pump 36 may be removed, and, in addition, a water temperature sensing device, such as a thermocouple indicated diagrammatically by numeral 32, is operatively mounted in one side of boiler chamber l2. It is of course, now necessary that thermocouple 32 be used as the activating device for control means 24.

In this embodiment upon the water in boiler 12 being cooled below the setting of thermoco'uple 32, a signal will be generated by thermocouple 32 to activate control means 24 and permit feeding of fuel to burner 18. Of course, if the system is used as a hot water heater, then thermostat 28 would not be utilized.

By-pass valve 38 is shown to be diagrammatically connected to control means 24, and is responsive thereto to permit selective amounts of heated water to be pumped to the radiator or tap-olf system 48. Valve 38 is differentially positionable between a fully open or fully closed position to provide a by-pass arrangement to the boiler system. Accordingly, with the valve fully open a circulating system which includes pump 36, tap-off utilization device 48, feed pipe 39 and return piping 40, but excluding the boiler 12 would be utilized. This, of course, would represent a mere recirculating condition to the tapoff utilization device 48. The other extreme point of operation is with by-pass valve 38 in a fully closed position; in the fully closed position the pump and tap-off utilization device 48 would be in circuit with the hot water feed outlet line 39 and return line 40. Accordingly, selective differential lposition between either extreme permits a metered amount of cooperation of the tap-oli utilization device 48 with the boiler system to permit the desired amount of heat thereto.

Thermocouple 19 in a hot water supply system is also provided proximate to pilot 21 in a heat sensing position thereto. It is, of course, realized that pilot 21 is provided with a llame which is continuously burning. Accordingly, upon turn-olf valve 23 Supplying fuel to burner 18 under the command of control means 24, pilot light 21 is opera-ble to ignite the gas and air mixture to permit ignition to Ioccur in the burner chamber 15. It would, accordi-ugly, be obvious that we would not want the burner control box 24 to permit fuel ow through valve 23 to s) burner 18 with the failure in pilot light 21. This is because of the fact that the build-up of gas in the -burner chamber could result in an explosion with the attendant loss of life .and property. Accordingly, thermocouple 19 being in heat responsive or flame responsive communication with pilot 21 is operable to sense the llame failure thereat and turn oit control means 24 in the event of a Itiame failure. Thermocouple 19, therefore, acts as a safety device to cut off control means 24 and prevent activation thereby by either thermostat 28 or thermocouple 32 in the event of flame failure of pilot 21.

Mode of operation Returning now to the heat exchange system, we disclose in FIG. 1 a water or steam lchamber 12 made up of walls 41 through 44 which is mounted above burner 18 upon heating surface plate 16. Chamber 12 is surrounded by an air envelope on the four lateral sides and upper extremity thereof. The water/steam chamber 12 has alternate rows of tubing which extend through the chamber. These rows provide passage-ways through which air travels by way of convection currents. As shown in FIGS. l and 2, the lateral walls of the chamber are integrally formed with a plurality of spaced apart rows of pipes. Each row including a plurality of -tubes 13 or 14 in parallel longitudinal relationship to each other. Therefore, we can see a plurality of alternate parallel rows of tubes 13 extending the entire elevational dimension of boiler 12. Transversely thereto a second plurality of parallel rows of pipes 14 are placed transverse to the rst set. These rows of superimposed transverse adjacent rows being suitably sealed in the Walls of the chamber 12 to prevent any escape of the water contained therein to the outer air chamber surrounding boiler chamber 12. Another way of describing the above boiler chamber 12 construction is to think of the pipes 13 as forming a first matrix of parallel tubes, and pipes 14 as forming a second matrix of parallel tubes. We can then say that the rst and second matrix of parallel tubes are in such relationship that immediate adjacent rows are in substantial longitudinal transverse relationship to each other.

It should hereat again be emphasized that prior art devices which only utilized a heating surface at the bottom of a water tank, and then counted `upon cond-uction to heat the water of the tank obviously required a long dur-ation of time to accomplish the desired heating of the water to the selected temperature. Furthermore, the prior art devices which encompassed a flue shell to -coaxially with the boiler and thus form an annular ue of combustion gases about the inner duid chamber, and, accordingly, count upon convection to carry the heated air to the surrounding inner wall chamber provides an improvement over the above mentioned heat exchanger device, but obviously has its shortcomings. On the other hand, my device `which provides a plurality of tube passageways through the boiler chamber results in the delivery of heat by way of hot air convection currents through the tubes to every square inch of the water contained in the boiler, and, accordingly, results in a speedy heating of the water contained in boiler 12. An added feature of the invention is that the desired water temperature of the water once obtained may be maintained at that desired level by a minimum amount of fuel expenditure, and it has been found that upon boiler 12 obtaining the desired temperature that burner 18 may be turned olf and the heat supplied Iby pilot light 21 is suiiicient to maintain the water temperature of the boiler at this desired level of long periods Vof time.

One reasonable explanation of the operation of our system is that burner 13 directly transmits heat to the heating surface 16 4and thereby immediately heats the water proximate the heating surface in boiler 12 by conduction. The heated water in turn loses heat to the air envelope contiguously surrounding the lower portion of the chamber. The heat results in hot air convection currents to rise toward the top portion of the chamber. The hot air convection currents then pass through the transversely yoriented plurality of tubes honeycombing the boiler chamber, and, thereby give up its heat to the surface of the tubes to heat the water contained therein. It can, accordingly, be seen that the water contained in boiler 12 will be heated by air convection currents as Well as by direct conduction, and, therefore, since the heat will be supplied to the boiler 12 at a plurality of differential levels it can be appreciated that the fluid content thereof will be heated in a substantially smaller period of time than would be capable by the prior art boiler designs.

In addition, while FIGS. 1 and 2 indicate that the tlue 33 which is used to conduct the hot gases or exhaust hot air developed in burner chamber 15 to the outer atmosphere may -as an alternative be routed into the air cha-mber, and, accordingly, provide additional heat to the air contained therein. It can thus be seen that the air enclosed `by chamber 11 could be heated by this additional heat source, .and the heat transfer by the air convection through the ltube passageways will result in even speedier heating of the water contained therein.

I claim:

1. A boiler structure comprising, a fluidtight boiler chamber, an outer hermetically sealed chamber surrounding said boiler, a fluid medium between said boiler and said outer chamber, said boiler chamber having -a multiplicity of horizontal tubes arranged in vertical rows and integrally formed in the Wall thereof and passing therethrough for -communication with said fluid, successive rows of said tubes -being transverse with respect to one another, the interior of said tubes communicating with said Huid chamber permitting the rapid exchange of heat from one part of said boiler to the other by convection of fluid currents in said chamber, and heating means 1ocated below and in heat exchange relationship with said boiler.

2. The combination as defined in claim 1, wherein said fluidtight boiler chamber is substantially filled with water, and said fluid medium i-n said outer chamber is air.

References Cited by the Examiner UNITED STATES PATENTS 366,040 7/1887 Snyder 122-494 376,390 1/ 1888 Morrison 126-10'1 I1,067,689 7/1913` Spotts 122-406 2,070,535 2/1937 Hansen 122-494 2,617,391 10/1952 Raymond 122-494 3,145,762 8/1964 Hassa 158-125 FREDERICK L. MATTESON, I R., Primary Examiner. KENNETH W. SPRAGUE, Examiner. 

1. A BOILER STRUCTURE COMPRISING, A FLUIDTIGHT BOILER CHAMBER, AN OUTER HERMETICALLY SEALED CHAMBER SURROUNDING SAID BOILER, A FLUID MEDIUM BETWEEN SAID BOILER AND SAID OUTER CHAMBER, SAID BOILER CHAMBER HAVING A MULTIPLICITY OF HORIZONTAL TUBES ARRANGED IN VERTICAL ROWS AND INTEGRALLY FORMED IN THE WALL THEREOF AND PASSING THERETHROUGH FOR COMMUNICATION WITH SAID FLUID, SUCCESIVE ROWS OF SAID TUBES BEING TRANSVERSE WITH RESPECT TO ONE ANOTHER, THE INTERIOR OF SAID TUBES COMMUNICATING WITH SAID FLUID CHAMBER PERMITTING THE RAPID EXCHANGE OF HEAT FROM ONE PART OF SAID BOILER TO THE OTHER BY CONVECTION OF FLUID CURRENTS IN SAID CHAMBER, AND HEATING MEANS LOCATED BELOW AND IN HEAT EXCHANGE RELATIONSHIP WITH SAID BOILER. 